T IPS ON B UILDING A BEST R OBOT Joe Marshall Kansas BEST

1 ST S TEP : READ the RULES and Technical Data Package 2

F OLLOW A N E NGINEERING P ROCESS Define the Problem Brainstorm: Strategy & Design Evaluate: Strategy & Design Select Strategy & Prelim Design (s) Build PrototypesDetail DesignConstructionTestingDeliver Product

O RGANIZING A BEST TEAM Carefully read the rules and the technical data. Review the construction materials allowed. Designate a key person and assistant to specialize in each of the following areas: Game Rules Robot tasks and strategy Joystick and CORTEX Microcontroller Batteries and Chargers Mechanical/Structural systems Materials Documentation Double duty may be necessary. Read the rules and technical data again 4

B UILD & F OLLOW A S CHEDULE 9/21/2013 5

R OBOT A TTRIBUTES R EQUIRED Robot is required to fit in 2 foot cube at start Weight not to exceed 24 pounds Robot to be built only with kit materials 6

R OBOT D ESIGN T ARGETS Durability/Reliability Design & build to be strong (“Robust”) Easy to build, maintain & repair Good electrical connections Allow Strategy Versatility Do “Good” in more than one way Able to change strategy during match Operability (Multiple Drivers Required) Easy to run Manipulator(s) easy to operate 7

8 88 BEST Robot Kit Your robot must be made entirely out of the kit materials

C ONSUMABLES VS. R ETURNABLES Consumables are for you to use and keep Wood, Metal, PVC, Hardware… Returnables are to be returned in original condition Motors, Servos, VEX system… Exception: Servo Horns and cog belt are allowed to be cut/modified but must be returned List of Consumables/Returnables is in your kit 9 9/21/2013

10 BEST Robot Control VEX System

K EY VEX S YSTEM P ARTS Joystick (transmitter) & batteries CORTEX Microcontroller easyC programming software Programming cable & USB A-A cable Four external motor controllers 2 large and 2 small motors Servo Power Adapter Cables Screw terminal interface cables 7.2 volt 3000 mAh batteries & chargers 2 VexNet USB Keys (Wireless comm) 11

W HAT C AN Y OU C ONTROL ? Robot movement, manipulation of game pieces & autonomous actions Two Large motors Two small motors Four servos Controller has 6+ channel controls All motors and servos can be used simultaneously 12

13 VEX J OYSTICK Channels 1 &2 on right stick Channels 3 &4 on left stick Channels 5 &6 are buttons on top side (non-proportional) Buttons on top are customizable- (all buttons are) VEXnet g key Communicates with CORTEX Microcontroller

VEX J OYSTICK T OP 14

J OYSTICK B ATTERIES 15 Ni-MH type batteries and charger are provided. Fully charged batteries last about two hours. Ni-MH, Ni-Cad or Alkaline AAA batteries are OK, but do not mix. During games on Mall and Game Days, Joystick power will be provided by the Game Floor. Batteries are required in the pits.

J OYSTICK B ATTERY C HARGER 16 Use only for Ni-MH batteries. Charging six discharged batteries takes over one hour.

17 CORTEX M ICROCONTROLLER CORTEX contains: master power switch and protection 8 motor and servo outputs Digital inputs and outputs Analog input and outputs 7.2 volt robot battery connection. Programmed by a computer using easyC software

18 CORTEX M ICROCONTROLLER Mounts on Robot with screws Communicates with Joystick through VEXnet key Powered by 7.2 volt robot battery 9 volt backup battery

CORTEX M ICROCONTROLLER 19 Motor Controllers or Servo Power Adapter Cables can be plugged into positions 2 through 9 Positions 1 & 10 are not to be used. Servos plug into end of Power Adapter Cables The BEST Default Program installed in the CORTEX assigns positions for Motor Controllers. Unused Motor Controller positions can be used for Servo Power Adapter Cables 2013 Kansas BEST

CORTEX M ICROCONTROLLER Digital input/outputs can be used for robot control. The BEST Default Program assigns some positions for motor/servo limit switches There are 8 Analog input/outputs.

21 S ERVO P OWER A DAPTER C ABLES  These cables install between the CORTEX and servos  Regulates voltage to the servos

O THER C ABLES 22 Motor Controller (speed control) - 4 Screw Terminal Motor Interface Cable - 4 Screw Terminal Sensor Interface Cable - 8

23 T YPICAL VEX S YSTEM H OOKUP

7.2 V OLT B ATTERY C HARGER 24 It takes about three and a quarter hours to charge a completely discharged battery.

B ATTERIES 7.2 volt Drive Batteries Only recharge them with the supplied charger (peak charger). Joystick Batteries Fully charged batteries should last about 2 hours. Suggestions Assign one person to be responsible for keeping the Joystick and robot 7.2 V batteries charged. Adequately discharge batteries prior to charging. 25

26 VEX System: Programming

P ROGRAMMING P ROGRAM O PTIONS Simulink Robot C Easy C 27

CORTEX P ROGRAMMING O PTIONS Use the existing default program in the CORTEX. -OR- Modify or add code to the existing program -OR- Build a robot program from scratch. 28

29 VEX S ETUP FOR P ROGRAMMING Joystick and CORTEX Microcontroller keys removed and USB A-A Cable installed. Programming Cable attached to Joystick interface. Robot battery, motors and servos can be connected during programming and hardware run (good program checkout). Programming can be done using the VEXnet keys instead of the USB A-A cable, but is not recommended.

O PTIONAL CORTEX P ROGRAMMING 30 No battery needed during programming.

P ROGRAMMING ON M ALL & G AME D AY There are no restrictions on the program used on the CORTEX Microcontroller except no output is allowed from motor output positions 1 and 10. Each team may have one laptop computer in their pit. A computer is considered a support tool. Changing the Cortex program during the competition (between rounds) is acceptable, but not recommended. 31

More about Robots Kansas BEST

W IRING T IPS Make sure plug-in and screw attach wire connections are tight (CORTEX, motors, etc.). Tin (with solder) bare wires prior to use in clamp-up joints or soldering a wire into a connection. Make good solder joints. They should be smooth and shiny, not dull gray. Keep wires short as possible (Do not cut Returnable Kit wires). Use a continuity checker to make sure joints are good.

M OTOR M OUNTING Mounting motors by motor front face using Motor Mounting Kit plates and screws is recommended. Motor gear case area can be used to stabilize motor, but do not use power section.

35 M OTOR M OUNTING K IT  Mounting plates are.09 thick aluminum.  Use only the screws provided in Motor Mounting Kit.  Plates are part of the Consumable Kit, so may be bent and cut as needed.

W HEEL A TTACHMENT P OSSIBILITIES These are possible ways to mount the wheels and large pulleys on the drive motors. These are not the only ways, but have been used reliably in the past. 36 ½” AL

P OSSIBLE U SE OF C OGGED B ELT One possible use of cogged belt strip. Won’t work where continuous rotation is required.

O THER P OWER -T RANSMISSION I DEAS String and Pulleys Cog and Sprocket Gears Velcro friction drive Rubber friction drive Solid Linkages Direct Drive Infinite other possibilities! 38

39 K EEPING T HINGS R UNNING Always turn-on the Joystick before turning on the CORTEX (robot). Always turn-off the Joystick after the CORTEX is turned off. Don’t let servos hum. They do this when they are jammed or overloaded. Keep dust and dirt away from CORTEX and motors. Remove them from robot or cover before painting, sanding, filing, etc. Note all the little plug-in holes in the CORTEX and openings in the back end of the motors.

P AST R OBOT P ROBLEMS  Robot does not fit in two foot cube  Maintain ½ inch safety margin  Wheels fall off  Motors are not securely mounted  Motor/servo power exceeded  Poor wiring (Intermittent connections)  Lack of robust design/construction  Poor mechanical fastening  Lots of duct tape used  Paint on Returnable Kit parts (not allowed)

HELP!  Help on the Web!  BRI Website- Q&A, Rules, Forum: www. bestinc.org/  Kickoff Day Presentations: kansasbest / Generic Kit Notes 41

L AST W ORDS Have Fun & Read the Rules And Technical Data